Storage system capable of managing a plurality of snapshot families and method of operating thereof

A storage system comprising a control layer and a cache memory therein, the control layer configured to manage a snapshot family (SF) constituted by hierarchically related SF members and mapped by a SF mapping data structure configured to provide logical-to-physical mapping for SF members,

• wherein the control layer is further configured to identify delta-data between two points-in-time by providing at least the following:
• generating successive snapshots Si and Si+1 corresponding to the two points-in-time;
• upon generating the snapshot Si+1,
• searching the cache memory for data blocks associated with snap_version identifier indicative of snap_version=i, thereby yielding cached delta-metadata, wherein snap_version identifier associated with a given data block is indicative of the latest SF member existing at the time of writing the given data block to the cache memory;
• searching the SF mapping data structure for destaged data blocks associated with snap_version identifier indicative of snap_version=i, thereby yielding destaged delta-metadata, wherein the SF mapping data structure is configured to associate a given physical address with snap_version identifier indicative of the latest snapshot existing at the time of writing to the cache memory data corresponding, when destaged, to the given physical address;
• and
• joining the cached delta-metadata and the destaged delta-metadata, thereby yielding delta-metadata indicative of the delta-data between points-in-time corresponding to the successive snapshots with Snap_ID=i and Snap_ID=i+1.

A non-transitory computer readable storage medium comprising computer readable program code embodied therein for operating storage system comprising a control layer with a cache memory and operable to manage a snapshot family (SF) constituted by hierarchically related SF members and mapped by a SF mapping data structure configured to provide logical-to-physical mapping for SF members, the computer readable program code causing the control layer to identify delta-data between two points-in-time by providing, at least, the following:

• generating successive snapshots Si and Si+1 corresponding to the two points-in-time;
• upon generating the snapshot Si+1,
• searching the cache memory for data blocks associated with snap_version identifier indicative of snap_version=i, thereby yielding cached delta-metadata, wherein snap_version identifier associated with a given data block is indicative of the latest SF member existing at the time of writing the given data block to the cache memory;
• searching the SF mapping data structure for destaged data blocks associated with snap_version identifier indicative of snap_version=i, thereby yielding destaged delta-metadata, wherein the SF mapping data structure is configured to associate a given physical address with snap_version identifier indicative of the latest snapshot existing at the time of writing to the cache memory data corresponding, when destaged, to the given physical address;
• and
• joining the cached delta-metadata and the destaged delta-metadata, thereby yielding delta-metadata indicative of the delta-data between points-in-time corresponding to the successive snapshots with Snap_ID=i and Snap_ID=i+1.